package org.apache.maven.lifecycle.internal;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import org.apache.maven.project.MavenProject;

import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.TreeSet;

/**
 * Context of dependency artifacts for a particular project.
 * 
 * @since 3.0
 * @author Benjamin Bentmann
 * @author Kristian Rosenvold (class extract only)
 *         <p/>
 *         NOTE: This class is not part of any public api and can be changed or deleted without
 *         prior notice.
 */
// TODO: From a concurrency perspective, this class is not good. The combination of
// mutable/immutable state is not nice
public class DependencyContext {

  private static final Collection<?> UNRESOLVED = Arrays.asList();

  private final MavenProject project;

  private final Collection<String> scopesToCollectForCurrentProject;

  private final Collection<String> scopesToResolveForCurrentProject;

  private final Collection<String> scopesToCollectForAggregatedProjects;

  private final Collection<String> scopesToResolveForAggregatedProjects;

  private volatile Collection<?> lastDependencyArtifacts = UNRESOLVED;

  private volatile int lastDependencyArtifactCount = -1;

  public DependencyContext(MavenProject project, Collection<String> scopesToCollect, Collection<String> scopesToResolve) {
    this.project = project;
    scopesToCollectForCurrentProject = scopesToCollect;
    scopesToResolveForCurrentProject = scopesToResolve;
    scopesToCollectForAggregatedProjects = Collections.synchronizedSet(new TreeSet<String>());
    scopesToResolveForAggregatedProjects = Collections.synchronizedSet(new TreeSet<String>());
  }

  public MavenProject getProject() {
    return project;
  }

  public Collection<String> getScopesToCollectForCurrentProject() {
    return scopesToCollectForCurrentProject;
  }

  public Collection<String> getScopesToResolveForCurrentProject() {
    return scopesToResolveForCurrentProject;
  }

  public Collection<String> getScopesToCollectForAggregatedProjects() {
    return scopesToCollectForAggregatedProjects;
  }

  public Collection<String> getScopesToResolveForAggregatedProjects() {
    return scopesToResolveForAggregatedProjects;
  }

  public boolean isResolutionRequiredForCurrentProject() {
    return lastDependencyArtifacts != project.getDependencyArtifacts()
        || (lastDependencyArtifacts != null && lastDependencyArtifactCount != lastDependencyArtifacts.size());
  }

  public boolean isResolutionRequiredForAggregatedProjects(Collection<String> scopesToCollect,
      Collection<String> scopesToResolve) {
    boolean required = scopesToCollectForAggregatedProjects.addAll(scopesToCollect)
        || scopesToResolveForAggregatedProjects.addAll(scopesToResolve);
    return required;
  }

  public void synchronizeWithProjectState() {
    lastDependencyArtifacts = project.getDependencyArtifacts();
    lastDependencyArtifactCount = (lastDependencyArtifacts != null) ? lastDependencyArtifacts.size() : 0;
  }

}
